China warned Monday that Britain was heading down "a wrong path" as Foreign Secretary Dominic Raab was expected to announce the suspension of an extradition treaty with Hong Kong, raising tensions between the countries.
Wang Wenbin, spokesman for China's foreign ministry, told a regular press briefing that Beijing would "firmly counter" any interference in its internal affairs, also slamming suggestions it was mistreating minorities in Xinjiang as "slander".
"We urge the UK not to go further down this wrong path, in order to avoid further damage to China-UK relations," Wang said.
"Recent erroneous remarks and measures concerning Hong Kong have seriously violated international law and basic norms governing international relations... China strongly condemns this and firmly opposes it."
A new security law imposed by China on Hong Kong last month has drawn widespread criticism in Britain and elsewhere, and Raab is due later Monday to announce a package of measures similar to those already introduced by the United States, Canada and Australia.
They are expected to include the suspension of an extradition treaty.
Tensions between Hong Kong's former and current rulers have soared over a number of topics recently.
Britain recently bowed to sustained pressure from Washington and ordered the phased removal of Chinese telecoms giant Huawei from its 5G network despite warnings of retaliation from Beijing.
Britain's Supreme Court president, meanwhile, suggested last week that the two British judges serving in Hong Kong's Court of Final Appeal -- under the terms of the territory's handover agreement with China in 1997 -- could stand down unless the rule of law was guaranteed in the semi-autonomous city.
Wang said Beijing would "oppose interference in Hong Kong affairs by outside forces" and that judicial independence was "not affected" by the new security law.
He also hit back at comments by Raab that accused Beijing of human rights abuses against ethnic and religious minorities in the northwest region of Xinjiang.
Raab told the BBC on Sunday that it was "clear that there are gross, egregious human rights abuses going on... it is deeply, deeply troubling."
Wang called the comments "nothing but rumours and slander".
"The Xinjiang issue is not about human rights, religions or ethnic groups at all, but about combating violence, terrorism and separatism," he said.
Rights groups and experts estimate that more than one million ethnic Uighurs and other mostly Muslim minorities have been rounded up into a network of internment camps, which China says are facilities for job-training and to steer people away from extremism.
Raab said reports of forced sterilisations and mass detentions in Xinjiang required international attention, and that Britain "cannot see behaviour like that and not call it out".
But Wang said the forced-sterilisation reports were "complete nonsense", and that the Uighur population had more than doubled in the past four decades.
Exiled Uighurs this month called for the International Criminal Court in the Hague to investigate China for genocide and crimes against humanity, filing a huge dossier accusing China of rights abuses including forcibly sterilising women.